The invention relates to a process and apparatus for treating biogenic residues, particularly sludges, preferably in the area of a clarification 
plant. Biogenic residues with a variable dry substance are subjected to aerobic 
drying until an energy-independent 
thermal treatment can be carried out. During the 
drying process, evaporated water is discharged in an 
odor-free condition without releasing freely volatile components, the dried 
sludge is intermediately stored a number of times and then utilized in preferably a number of successive 
thermal treatment steps. The two-stage cleaning of the 
stream of 
waste gas includes a dust collection unit and an adsorption unit. The 
waste heat is recycled through a 
heat exchanger to generate heat and 
electricity. The apparatus for carrying out the process includes a wet 
sludge storage container (1), a low temperature 
drying system (2), storage containers (3, 5) for 
intermediate storage of the dried biogenic residues, and a 
thermal treatment system with one or more thermal treatment steps (7, 8). Cleaning of the 
flue gas takes place preferably by means of a primary cleaning step (10) and a secondary cleaning step (11) for adsorption, for example, with clarified water. 
Energy recovery (9) from the hot 
waste gas is ideally carried out before the 
flue gas cleaning.